Go patch committed: Insert type conversion for closure function value

[Ian Lance Taylor]

This patch by Than McIntosh changes the Go frontend, in
Func_expression::do_get_backend, when creating the backend
representation for a closure, to create a backend type conversion to
account for potential differences between the closure struct type
(where the number of fields is dependent on the number of values
referenced in the closure) and the generic function descriptor type
(struct with single function pointer field).  Bootstrapped and ran Go
testsuite on x86_64-pc-linux-gnu.  Committed to mainline.

Ian
-------------- next part --------------
Index: gcc/go/gofrontend/MERGE
===================================================================
--- gcc/go/gofrontend/MERGE	(revision 250326)
+++ gcc/go/gofrontend/MERGE	(working copy)
@@ -1,4 +1,4 @@
-c49ddc84f3ce89310585aad23ab6e51ef5523748
+3d9ff9bc339942922f1be3bef07c6fe2978ad81a
 
 The first line of this file holds the git revision number of the last
 merge done from the gofrontend repository.
Index: gcc/go/gofrontend/expressions.cc
===================================================================
--- gcc/go/gofrontend/expressions.cc	(revision 249799)
+++ gcc/go/gofrontend/expressions.cc	(working copy)
@@ -1204,7 +1204,14 @@ Func_expression::do_get_backend(Translat
   // expression.  It is a pointer to a struct whose first field points
   // to the function code and whose remaining fields are the addresses
   // of the closed-over variables.
-  return this->closure_->get_backend(context);
+  Bexpression *bexpr = this->closure_->get_backend(context);
+
+  // Introduce a backend type conversion, to account for any differences
+  // between the argument type (function descriptor, struct with a
+  // single field) and the closure (struct with multiple fields).
+  Gogo* gogo = context->gogo();
+  Btype *btype = this->type()->get_backend(gogo);
+  return gogo->backend()->convert_expression(btype, bexpr, this->location());
 }
 
 // Ast dump for function.